1. Field of the Invention
The present invention relates to a layer jump control apparatus of a multilayer disk and a method thereof, in particular to a layer jump control apparatus of a multilayer disk and a method thereof which is capable of jumping accurately and rapidly on a request position by setting operation voltage variably in order to jump on a layer of the multilayer disk having at least two different record layers.
2. Description of the Prior Art
In general, an optical disk operation apparatus embodies a video and an audio by reading data recorded on the optical disk with optical pickup and releasing compression by processing the read signal.
The optical pickup reads the needed data by throwing laser on a set position of the optical disk and picking up the optical light.
In the present times, a DVD (Digital Versatile Disk) has spread as the optical disk. The digital versatile disk is the multilayer disk having at least two layers, and it can store larger amount of data than the conventional optical disk.
Meanwhile, in order to read the data recorded on the multilayer disk by the optical pickup, it can be transferred to each layer. In order to make an optical pickup 20 jump on the other layer, when a focus servo operation is OFF, the optical pickup can jump on the other layer by ascending an inner focus lens of the optical pickup rapidly by influence of a minus offset maintained itself.
However, in the above-mentioned method, because the inner focus lens of the optical pickup ascends rapidly, it passes a target layer.
It is possible to solve above-mentioned problem by performing the servo operation while ascending the focus lens slowly after descending the focus lens sufficiently.
The construction and operation of the above-described optical disk will now be described as below.
FIG. 1 is a block diagram illustrating a construction of a general optical disk apparatus. It comprises a multilayer disk 10 having at least two record layers, an optical pickup 20 for reading data recorded on the multilayer disk 10, a spindle motor 50 for rotating the multilayer disk 10, a RF unit 30 for generating a servo error signal (namely, a tracking error, hereinafter, it is referred to TE) and a focusing error (hereinafter, it is referred to FE) from a signal detected from the optical pickup 20 and outputting a binary signal by performing wave-filtering of a regenerative RF (radio Frequency) signal, a drive unit 60 for operating the spindle motor 50 and optical pickup 20, a digital signal processing unit 40 for restoring the binary signal outputted from the RF unit 30 into the original data and controlling the operation of the drive unit 60 by the TE and FE signal, and a microcomputer 70 for outputting a control order to the digital signal processing unit 50.
The operation of the above-described general optical disk apparatus will now be described.
When the regenerative signal is inputted to the microcomputer 70 from outside, the microcomputer 70 operates the spindle motor 50 by controlling the drive unit 60, and operates the multilayer disk 10. In addition, the microcomputer 70 detects a reflected light by controlling the optical pickup 20. The detected signal is inputted to the RF unit 30. The RF unit generates the TE, FE, and regenerative FR signals by the inputted signal. When the focusing and tracking error signals are inputted to the microcomputer 70, the microcomputer 70 transmits the control signal to the digital signal processing unit 40 by the inputted error signal. The digital signal processing unit 40 controls the optical pickup 20 through the drive unit 60 in accordance with the inputted control signal. The optical pickup determines a target record layer and a track by the inputted control signal.
The data recorded on the multilayer disk 10 is read by the above-described processes, is converted into regenerative data in the digital signal processing unit 40, and is outputted.
The operation when a layer up/down order is applied to the multilayer disk drive operation apparatus will now be described in detail with reference to accompanying FIGS. 2 and 3.
FIG. 2 is a construction profile illustrating a focusing actuator for operating the inner focusing lens of the optical pickup in the general multilayer disk, the position of the focusing lens is adjusted by the voltage applied to the focusing actuator, it can jump on the other layer of the multilayer disk.
FIG. 3 is a flow chart illustrating a layer jump operation of the conventional optical disk operating apparatus. When a layer jump order is inputted from the outside to the microcomputer 70 S81, the microcomputer 70 turns off the tracking and sled servo operation of the optical pickup 20 S82, and delays about for 5 msec in order to stabilize the optical pickup 20 S83.
The servo is the apparatus for adjusting automatically the optical pickup on an adjustable position of the multilayer disk. It can be divided into the tracking servo, sled servo, and focusing servo.
The tracking servo adjusts the optical pickup 20 accurately on a pit of a target track of the multilayer disk by adjusting it to left/right direction on the basis of the tracking error signal generated and outputted from the RF unit 30.
The sled servo adjusts the position of the request track by adjusting the optical pickup 20 to radial direction from the center of the multilayer disk.
The focusing servo adjusts the optical pickup 20 to vertical direction on the basis of the focusing error signal generated and outputted form the RF unit 30.
Meanwhile, after 5 msec passes, the microcomputer 70 turns off the focusing servo operation S84, and delays for 5 msec in order to stabilize the optical pickup 20.
By the above-described process, when the all servo operation is OFF, the microcomputer 70 transmits an instruction word $02 for layer jump to the digital signal processing unit 40.
The instruction word $02 is for descending the focus lens of the optical pickup vertically.
The digital signal processing unit 40 applies the focusing servo control voltage to the drive unit 60 by the inputted instruction word $02. The drive unit 60 controls to make the inner focus lens of the optical pickup 20 descend vertically for about 100 msec by the applied control voltage.
When the focus lens descends, the microcomputer 70 outputs an ascendant instruction word $03 of the focus lens of the optical pickup 20 to the digital signal processing unit 40.
The instruction word $03 is for ascending the focus lens of the optical pickup 20.
The digital signal processing unit 40 applies the operation voltage for ascending the focus lens of the optical pickup 20 to the drive unit 60 by the inputted instruction word.
The drive unit 60 applies the applied operation voltage to the focus actuator (depicted in FIG. 2) of the inner focus lens of the optical pickup 20, and ascends the focus lens vertically for about 20 msec S87.
As described above, when the focus lens moves, the microcomputer 70 transmits an instruction word $08 for turning on the focusing servo to the digital signal processing unit 40 S88.
The digital signal processing unit 40 transmits continually a FOK (Focus Okay) signal and a sense signal to the microcomputer 70. Because the transmitted signals are generated in order to jump on a superior record layer, the microcomputer 70 ignores the FOK signal and sense signal about the first layer among the transmitted signal, and observes continually the FOK signal and sense signal about the second layer.
The FOK (Focus Okay) signal is a signal which is outputted when the focusing operation of the focus lens is performed normally. The sense signal is a signal outputted from a sense circuit of the digital signal processing unit 40, its output is differentiated in accordance with a command on a microcomputer serial register, it is referred as a FZC (Focus Zero Crossing) for the focus servo control in the present invention.
When the digital signal processing unit 40 outputs the FOK signal and sense signal as high to the microcomputer 70 S89, the microcomputer 70 detects a descendant edge time point of the sense signal, and controls the digital signal processing unit 40 in order to make the focusing servo operation about the superior layer turn on in accordance with the transmitted instruction word $08, the requested layer jump operation is finished.
However, in the layer jump method on the multilayer disk, when a jump request occurs, the focus servo operation is performed while ascending the lens slowly after descending the focus lens sufficiently, accordingly long time for about 200 msec is required in the layer jump on the multilayer disk.
In order to solve above-mentioned problems, a DSP (Digital Signal Processing) chip for focus up/down is used for the some optical operation apparatus. The DSP chip is used only in focus up/down for making focus at initial times, and it is set as a too low value for the focus operation voltage for plural layers focus control, accordingly it is difficult to perform accurate control and the time can be delayed.
The object of the present invention is to provide a layer jump control apparatus of a multilayer disk and a method thereof which is capable of jumping on a request position accurately and rapidly by setting variably operation voltage inputted to an optical pickup operating the multilayer disk. The other object of the present invention is to provide a layer jump control apparatus of a multilayer disk and a method thereof which is capable of controlling jump accurately and rapidly by adjusting appropriately kick/brake time in layer jump.
In order to achieve the objects of the present invention, the embodiment of the present invention comprises an optical pickup including an object lens reading data recorded on a disk having at least two layers, a digital signal processing unit for outputting a control signal for focus servo control from a signal read from the optical pickup, and restoring the original signal from the read signal, a control unit for outputting a control order for layer jump to the digital signal processing unit in the layer jump, controlling focusing operation of a target layer from the signal outputted from the digital signal processing unit in accordance with the control order, and outputting a different control signal in accordance with the target layer transferring position, and an operation voltage unit for operating variably the focus lens of the optical pickup by the control signal outputted from the control unit.
The embodiment of the present invention comprises converting a focusing servo into inactive state when a layer jump request between record layers of the multilayer disk is inputted from outside, performing vertical transferring of the focus lens to the layer jump request position by setting variably the operation voltage of an inner focus lens of an optical pickup, and converting the focusing servo into active state on the present position of the focus lens on the basis of a FOK signal and a FZC signal detected in accordance with the transferring operation.
The other embodiment of the present invention comprises a reader for reading data recorded on a disk having at least two layers, a servo control unit for outputting a signal for controlling vertical transferring time of the reader from the signal outputted from the reader, an operation unit for operating the reader in accordance with a signal outputted from the servo control unit, and a control unit for controlling the servo control unit for focusing of the pertinent layer in layer jump request of the disk, and controlling the operation unit for outputting a variable voltage in accordance with a target layer transferring position.
The another embodiment of the present invention comprises confirming whether there is a layer jump request, transferring a pickup to the pertinent layer to the vertical direction in the layer jump request, and controlling the transferring speed to the vertical direction in accordance with a signal outputted by the transferring of the pickup.